<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

    <script type="text/javascript">

        let arr = ["a","b","c","d"];

        arr.splice(2,1)//删除索引为2的元素

        console.log(arr)

    </script>

</body>
</html>